In the study, men in their 20s and 30s who were healthy but overweight and leading sedentary lives were placed in three groups.

For 13 weeks, the first group didn’t exercise at all, the second did a moderate amount of exercise and the third worked out strenuously.

By the end of the 13 weeks, the sedentary group didn’t lose any weight, as was expected. However, the men in the group that exercised moderately lost an average of 7 pounds each, while the group that exercised the most lost an average of 5 pounds each.

While it’s not entirely clear why the group that exercised moderately — 30 minutes a day — were the most successful, The New York Times reports the food diaries of the men did hint at what had happened.

The men who exercised the most increased the size of their meals and snacks, says Mads Rosenkilde, the researcher who led the study. The group that exerted more energy ended up fatigued and spent more of their days sitting.

The men who exercised for only 30 minutes seemed more energized and satisfied throughout the day. The shorter exercise sessions let the men burn the calories without wanting to replace them as often, Rosenkilde says.

The men exercising half as much seemed more inspired to stay active.

“It looks like they were taking the stairs now, not the elevators, and just moving around more. It was little things, but they add up,” Rosenkilde tells The New York Times.

The study, however, was only short-term and didn’t include women, so more research is needed for more conclusive findings.